For non-P2P stuff like PayPal is very good because bank transfers are non-reversible. You can do G&S on PayPal and reverse that if you need to.
For P2P, stuff like Revolut, PayPal, whatever is still easier because you don't need to remember your bank account number. There is also no interoperability between banking apps either (the only interaction is through FASTER and your number). So you end up needing someone in the middle, like PayPal, which (in the end) is just doing bank transfers...not ideal but it is, at least, cheap.
Reason would suggest the latter will eventually change, but that day is not today.
Also, cross-currency transfers are significantly easier with apps. I agree that it is all a bit unnecessary but...banks are banks. In the UK, there has been a lot of competition and services are still (imo) dire.